用气相色谱法测定液状食品中四种对羟基苯甲酸酯类防腐剂

用毛细管气相色谱法实现了液状食品中4种防腐剂(对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯)的分离测定，各组分回收率为91．15～107．7％，检出限为0．5μg／mL，线性范围为0．2μg／mL～80μg／mL．线性相关系数大于0．999。     

毛细管电泳法分离检测三种肾上腺素类化合物

采用毛细管电泳法对去甲肾上腺素、去氧肾上腺素和异丙肾上腺素三种肾上腺素类化合物进行分离检测.在电泳运行缓冲液为100mmol/L NaH2PO4(pH=5.2)中,当分离电压为22kV时,三种肾上腺素类化合物在12min内达到基线分离.在最优的条件下,各组分的峰面积与待测物浓度在0.02-50μg/mL范围内呈良好的线性关系,检测限均为0.01μg/mL.将该方法用于加标尿样中上述三种分析物的测定,回收率为94.89%-105.9%.     

利用胶束电动色谱技术用于抗生素测定

采用毛细管胶束电动色谱技术对阿莫西林、氯唑两林、头孢氨苄、头孢噻肟、头孢唑林5种抗生素进行分离．18kV电压下，在溶有100mmol／LSI）S的硼酸盐缓冲溶液（20mmol／L，pH-8．9）中，采用二极管阵列检测器．在9min内可以完成对此5种抗生素的分离检测．线性范围0．1～250μg／mL．相关系数为0．9976～0．9994，检测限为0．01～0．13μg／mL．运用此方法对3种药物形式的抗生素进行同时检测．日间和日内的RSDs分别为3．95％～8．12％和1．51％～2．86％。迁移时间的日间和日内的RSDs分别为0．47％～1．11％和0.032％～0.295％．在尿样的测定中，日问和日内的RSDs分别为1．31％～6.07％和0.66％～7．65％，回收率为90％～110％．此外．还对分离条件对抗生素的迁移行为的影响做了理论探讨．     

毛细管电泳法分离检测三种鹿茸样品中天然性激素的研究

本文采用加入表面活性剂SDS和β-环糊精的Tris-硼酸作为电泳溶液体系，对毛细管电泳法分离测定雌三醇，雌二醇，雌酮，皮质酮，睾酮和孕酮等六种天然性激素的条件进行了探讨．使用200nm和250nm的检出波长，以上性激素的检出限(S/N=3)在0．13～0．25μg／mL的范围内，工作曲线的直线范围为0．50～30μg/mL；泳动时间的相对标准偏差小于2．0％，峰面积的相对标准偏差小于3．9％．将该法应用于梅花鹿、马鹿和糜鹿茸样品的粗提取液分析，并与HLPC法和放射免疫法进行了对照，其有效性得到了较好的证明．     

毛细管电泳仪测定土壤中氧化乐果的含量

应用高效毛细管电泳法对氧化乐果的含量进行了测定,研究了检测波长、缓冲体系、缓冲液pH、缓冲液浓度、SDS浓度和分离电压对氧化乐果测定的影响。在pH 7.5、20 mmol/L NaH2PO4-Na2HPO4缓冲液、30mmol/L SDS2、54 nm、25 kV下,氧化乐果的测定最佳.毛细管电泳仪测定氧化乐果的检测限为0.2μg/mL,线性范围为0.5~150μg/mL,相对标准误差RSD<3%。采用标准加入法,测定回收率在91.6%~101.2%.该方法应用于土壤中氧化乐果含量的测定,具有高效、快速、简便的特点.     

毛细管电泳安培检测法同时测定厚朴酚与和厚朴酚

采用毛细管电泳安培检测法对厚朴酚及和厚朴酚的分离测定进行了详细研究.工作电极为0.3 mm碳圆盘电极,30 mmol/L、pH10.0的硼砂-氢氧化钠为运行缓冲液,分离电压21 kV,检测电位0.95 V.在最优化实验条件下,两待测物在6 min以内完全基线分离.厚朴酚及和厚朴酚的线性范围分别为0.2~50μg/mL和0.4~60μg/mL,检测限分别为0.06和0.2μg/mL.应用于中药厚朴以及中成药霍香正气水和保济丸中厚朴酚及和厚朴酚的检测.     

毛细管电泳法检测微透析液中的头孢唑林钠

微透析(MD)与毛细管电泳(CE)相结合,原位、在体、实时监测了家兔血液中头孢唑林钠(Cefazolinsodium,CFZ)浓度的变化,并初步研究了CFZ的药代动力学.结果表明,在50mmol/L的硼砂(pH9.5)缓冲液,20kV分离电压,214nm紫外检测的毛细管电泳条件下,以环丙沙星为内标,CFZ在15min之内与内标物及透析液中的其他物质达到了良好的分离.在此条件下,CFZ测定的线性范围为1～300μg/mL,检出限为0.3μg/mL(3σ),绝对检出限为2.7×10-12g.微透析灌流速度为3μL/min,探针透析率为31.8±6.8%(n=3).测定结果经NDST药动学软件分析表明,CFZ在家兔体内的清除半衰期为24.5min.     

高效毛细管电泳法分离检测人体血浆中盐酸伪麻黄碱和磷酸可待因

建立毛细管区带电泳同时测定人体血浆中盐酸伪麻黄碱和磷酸可待因含量的方法.在75μm I.D×60cm未涂层石英毛细管中,以30mmol/L Tris-HCl为电泳缓冲溶液,分离电压为22kV时,两种被测组分在5min内达到基线分离.盐酸伪麻黄碱和磷酸可待因的检出限分别为0.50、0.30μg/mL,样品加标回收率在88%～95%之间,相对标准偏差（RSD）均小于5%.该方法简便、快速、准确,并成功用于人体血浆样品的分析.     

毛细管色谱法测定头孢美唑中的有机溶剂残留量

采用毛细管气相色谱法，以叔丁基甲醚为内标，用Agilent DB-200毛细管气相色谱柱和氢焰离子化检测器．同时测定了头孢美唑中甲醇、乙醇、二氯甲烷、三乙胺、乙酸乙酯、苯甲醚等6种有机溶剂残留量．6种溶剂的线性范围分别为0～480μg／mL（r=0．9996）、0—800μg／mL（r=0．9994）、0～96μg／mL（r=0．9990）、0～800μg/mL（r=0．9993）、0～800μg／mL（r=0．9995）、0～800μg／mL（r=0．9993）；平均回收率分别为100．1％、100．5％、101．2％、100．1％、100．7％和100．4％；相对标准偏差分别为0．90％、1．30％、1．18％、1．23％、1．52％、1．41％（n=9）．     

毛细管电泳法快速测定氧化乐果的含量

应用高效毛细管电泳法对氧化乐果的含量进行了测定,研究了检测波长、缓冲体系、缓冲液pH、缓冲液浓度、SDS浓度和分离电压对氧化乐果测定的影响.结果表明,在pH为7.5、20 mmol/L NaH2PO4-Na2HPO4缓冲液、10 mmol/L SDS、209 nm、25 kV的条件下,氧化乐果的测定效果最佳.测定氧化乐果的检测限为0.15μg/mL,线性范围为0.5～30μg/mL.采用标准加入法,测定回收率为92%～105%.该方法可成功应用于农田水样中氧化乐果含量的测定.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that